Improvement in casting iron kettles



C. McGINNISS.

Casing Metal Hollow Ware.

Patented July 20, 1858.

NITED STATES PATENT OFFICE.

CORNELIUS MOGINNISS, OF PITTSBURG. PENNSYLVANIA.

IMPROVEMENT IN CASTING IRON KETTLES.

Specification forming part of Letters Patent No. 20.95 H dated July 20, 1858.

To all whom it may concern:

Be it known that I, CORNELIUS McGINnIss, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in the Mode of Gasting Metallic Kettles and Hollow \Vare; and I do hereby declare that the following is a full, clear, and exact description thereof, reference part of this specification, in which Figure 1 represents one of the side pieces of the core. Fig. 2 is the centerpiece of the core. Fig. 3 represents the core and cope attached ready for casting the kettle. Fig. 4 is a section through the core and cope after the kettle is cast.

The old method of easing large hemispherical iron kettles by constructing a brick core ofthe size of the inside of the kettle and building over it a dome of brick called the cope on a frame-work, by which it may be lifted off the the core when the kettle is cast, (the necessary space being left between the core and cope for the kettle to be cast, is well known, and need scarcely be referred to here further than to remark that it is extremely awkward and inconvenient, and as afresh core and cope have to be built for every casting, and have to stand several days to become sufficiently dry before they can be used, this method is also very expensive and slow. To remove these difficulties the plan of constructingthe core and cope of iron was adopted, which would be much more convenient but for a practical difficulty which would entirely defeat the success of this method, and which it is the design of my improvement to obviate. The difficulty alluded to rises from the contraction of the iron of the casting as it cools around the core, which is so great that if the casting were allowed to cool without removing the .core it would burst, and thus be destroyed before it was entirely cold. It is necessary, however, that the core should remain in its place until the casting is sufficiently cool to retain its shape after the core is removed, and

by that time the contraction is so great and the casting binds so tightly around the upper edge or rim of the core that the core cannot be lifted out without some coutrivance be used to enable it to be removed without injury to the casting. Several plans have been tried, with more or less success, to accomplish this object, one of which is the cooling of the inner flask or core with water and removing it the moment it has sufficiently contracted to become loose; but this is apt to cause the core to crack. My invention, however, is designed to accomplish this essential end by a peculiar construction of the core itself, without the aid of any adventitious help. being had to the annexed drawings, forming I construct the core or inner part of the mold in which the kettle is to be cast in three pieces,

the two pieces a a, of the shape shown in Fig. 1, being alike, and each of them being nearly the half of the core, the third or center piece,b, of the shape shown in Fig. 2, being anarrow section of the core about three inches wide, and which, falling exactly between the two side pieces, a a, forin,when they are fastened together, the entire core. These three pieces are secured together by means of three screwbolts, 0 c c, which fit in grooves inprojections d d, &c., situated on the outside of the core, and so placed that when the pieces a, b, and a of the core are placed side by side the grooves in the corresponding projections will exactly come together, and the screw-bolt having a head at one end and a nut, 1 at the other will hold the parts firmly together. Grooves are used instead of bolt-holes in the projections, because it would be difficult, if not impossible, to withdraw and replace the bolt through an ordinary bolt-hole. By using grooves instead, the bolt may be very readily removed by slightly loosening the nut at the end of the bolt, when they can be lifted out of the groove. The cope h,or under part of the 1nold,is made in the usual form, and the inner surface of both core and cope are covered with sharp projections or points to hold the mud with which they are plastered. The surface of the mud against which the kettle is to be cast is made perfectly smooth and hemispherical by means of a trammcl in the ordinary way. The core a b a is then placed inside of the cope 71/, the kettles being cast right side up,and not inverted, as necessary when the core and cope are built ofbrick-work, as before described. Bolts 0 e are passed through holes in corresponding lugs, f f, in the core and cope, and, being screwed tight by nuts on the bolts 0 0, hold the core and cope in their right place, the space between the inner mud surface of the core and cope forming the matrix in which the kettle iscast. The melted metal is then poured into matrix through gates g g in the top or rim of the core. So soon as the castingissufticiently cool to retain its form without the aid of the core, and before it has shrunk so much as to crack or burst,the screw-bolts c c, &c., are removed by loosening the nuts 2' '1", &c., and the center piece,b,of the core is lifted out from between the side pieces, a a, and the screw-bolts c c, which fasten together the core and cope, being then with drawn,the side pieccs,a and a, of the core may be readily removed with perfect safety to the casting while the core and cope, having sustained no injury other than the ordinary wear and tear,are ready for further use. The same end may be accomplished by using a core divided into four or more sections secured together by hooks or bolts; but this I regard as substantially the same mode as that which I have already described. I

Having thus described my improvement in the mode of casting large iron kettles and other hollow ware, whatI claim as my invention, and desire to secure by Letters Patent, is-

Constructing the metallic core as hereinbefore described, of three or more pieces united by bolts so as to be readily detachable, one of which pieces is a narrow central strip, which may be removed after the kettle is cast and before it is sufficiently cool to remove the entire core, for the purpose of allowing the contraction of the casting Without danger of bursting.

CORNELIUS MGGINNISS.

Vitnesses:

J NO. 0. BUROHETT, SAMUEL BUOKINGHAM. 

